1. Field of the Invention
The present invention relates to an image forming apparatus having a process cartridge.
2. Description of the Related Art
In an image forming apparatus of the electrophotographic system, a toner image is transferred to a sheet, and the transferred toner image is fixed to the sheet. A process cartridge in which an image carrier and a developing device are integrally formed is used as a section for forming a toner image. Usually, a thermal pressure fixing device which performs fixation by means of heat and pressure is used in fixation of a toner image.
As a result of miniaturization of an image forming apparatus, a process cartridge and a fixing device are place in close proximity to each other. Consequently, there is a possibility that the process cartridge receives radiant heat from the fixing device to adversely affect an image carrier and a toner.
Therefore, a technique has been proposed in which a shutter disposed in a process cartridge is used for forming a gap between the shutter and a main unit of the process cartridge, and a fan is disposed to produce an air flow in the gap (for example, see JP-A-2-50169 JP-A-5-224476).
In the above two conventional arts, a single blower fan is placed in the vicinity of a process cartridge, and the single blower fan performs both air suction and exhaust, thereby causing a problem in that the cooling efficiency is poor.